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All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Post-flight analyses of the crystals from the M0003-14 quartz crystal microbalance experiment

Quartz Crystal Microbalances constructed by QCM Research were flown on the leading and trailing edges of the Long Duration Exposure Facility (LDEF) as one of the sub-experiments of M0003. Response of the crystals coated with 150 A of IN2O3ZnS was recorded during the first 424 days of the mission. A second QCM with crystals coated with 150 A was also flown but not monitored. The flight data and temperature profiles will be presented. After the flight, the QCM's were disassembled and analyzed. The samples included the crystals from the leading and trailing edge samples of both types of coatings along with the reference crystals which were inside the QCM housing. Analyses were performed by scanning electron microscopy, energy dispersive x ray analysis, x ray photoelectron spectroscopy, ion microprobe mass analysis, and reflectance spectroscopy in the infrared and ultraviolet/visible region. The crystals were contaminated predominantly with silicone compounds. The contamination is higher on the leading edge than on the trailing edge, and higher on the exposed crystal than on the reference crystals. No significant differences in composition of the In2O3 crystals were noted. Differences in the reflectance and surface analysis of the Zns crystals will be discussed.

Stuckey, W. K.↗
NASA NTRS1993

Post-flight analyses of the crystals from the M0003-14 quartz crystal microbalance experiment

Quartz Crystal Microbalances constructed by QCM Research were flown on the leading and trailing edges of LDEF as one of the sub-experiments of M0003. Response of the crystals coated with 150 A of In2O3 was recorded during the first 424 days of the mission. A second QCM with crystals coated with 150 A of ZnS was also flown but not monitored. After the flight, the QCM's were disassembled and analyzed in The Aerospace Corporation laboratories. The samples included the crystals from the leading and trailing edge samples of both types of coatings along with the reference crystals, which were inside the QCM housing. Analyses were performed by scanning electron microscopy, energy dispersive x-ray analyses, x-ray photoelectron spectroscopy, ion microprobe mass analysis, and reflectance spectroscopy in the infrared and UV/visible regions. The crystals are contaminated predominantly with silicone compounds. The contamination is higher on the leading edge than on the trailing edge and higher on the exposed crystals than on the reference crystals.

Stuckey, W. K.↗
NASA NTRS2006

Vacuum Ultraviolet Radiation Desorption of Molecular Contaminants Deposited on Quartz Crystal Microbalances

Recent quartz crystal microbalance measurements made in the Marshall Space Flight Center, Photo-Deposition Facility, for several materials, recorded a significant loss of deposited contaminants when the deposition surface of the microbalance was illuminated by a deuterium lamp. These measurements differ from observations made by other investigators in which the rate of deposition increased significantly when the deposition surface was illuminated with vacuum ultraviolet radiation. These observations suggest that the accelerated deposition of molecular contaminants on optically sensitive surfaces is dependant upon the contaminant being deposited and must be addressed during the materials selection process by common material screening techniques.

Albyn, Keith↗
NASA NTRS1975

ATS-6 - Quartz-Crystal Microbalance

The Quartz-Crystal Microbalance Experiment provided data on the possible return of contaminants to the exterior surfaces of the spacecraft. The experiment measures the change in resonant frequency of the crystal due to deposition of material on the surface. There has been no mass accretion corresponding to the firing of hydrazine thrusters to unload the spacecraft momentum wheels. There have been accretions corresponding to the firing of the cesium ion engines.

Rogers, J. F.↗
DOE OSTI2015

Interfacial study of the role of SiO 2 on Si anodes using electrochemical quartz crystal microbalance

One of the challenges associated with silicon as an anode material for Li-ion batteries is the formation of an unstable solid-electrolyte interphase which, forms continuously while consuming lithium and other components; and consequently contributes to irreversible capacity. To elucidate some of the details of the formation and subsequent dissolution of species formed during lithiation of silicon anodes we have produced thin film silicon electrodes and analyzed them during lithiation and delithiation using an electrochemical quartz microbalance with in-situ dissipation (EQCM-D). Measurements were conducted on electrodes with silicon alone and silicon with a silicon dioxide coating, and in EC:EMC and EC:DEC:FEC based electrolytes. Mass loss during lithiation was observed in both solvents systems when an oxide layer was present on the surface of the electrode. Solid state and solution NMR measurements indicate that the formation and dissolution of Li2O is the most likely cause of mass loss.

Anodes↗
DOE OSTI2021

New Insights on Plasmin Long Term Stability and the Mechanism of Its Activity Inhibition Analyzed by Quartz Crystal Microbalance

We used the research quartz crystal microbalance (RQCM) to monitor regulatory effects of plasmin and trypsin in the presence of their inhibitor α2-antiplasmin. The gold surface of quartz crystals was modified with a β-casein layer that served as a substrate for protease digestion. The addition of plasmin or trypsin as well as their mixtures with α2-antiplasmin resulted in an increase of resonant frequency, f, and in a decrease of motional resistance, Rm, depending on the molar ratio of protease: antiplasmin. At equimolar concentrations of protease and α2-antiplasmin (5 nM:5 nM) full inhibition of protease activity took place. Monitoring of plasmin activity on an hourly and daily basis revealed a prominent effect of autolysis and decrease of plasmin activity in freshly activated samples. The degree of inhibition as well as plasmin half-life (t1/2 = 2.48 ± 0.28 days) connected with its degradation was determined.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Label-free real-time acoustic sensing of microvesicle release from prostate cancer (PC3) cells using a Quartz Crystal Microbalance

Highlights: • Microvesiculating cells record loss of mass on a Quartz Crystal Microbalance. • Using the Quartz Crystal Microbalance microvesicles are measured at 0.24 pg. • The QCM-D reveals loss in viscoelastic properties in microvesiculating cells. - Abstract: Using a Quartz Crystal Microbalance with dissipation monitoring, QCM-D (label-free system) measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, we showed the attachment, over a 60 min period, of a monolayer of PC3 cells to the gold electrodes of the quartz crystal sensor, which had been rendered hydrophilic. That MVs were released upon BzATP stimulation of cells was confirmed by NTA analysis (average 250 nm diameter), flow cytometry, showing high phosphatidylserine exposition and by fluorescent (Annexin V Alexa Fluor® 488-positive) and electron microscopy. Over a period of 1000s (16.7 min) during which early apoptosis increased from 4% plateauing at 10% and late apoptosis rose to 2%, the Δf increased 20 Hz, thereupon remaining constant for the last 1000s of the experiment. Using the Sauerbrey equation, the loss in mass, which corresponded to the release of 2.36 × 10{sup 6} MVs, was calculated to be 23 ng. We therefore estimated the mass of an MV to be 0.24 pg. With the deposition on the QCM-D of 3.5 × 10{sup 7} MVs over 200s, the decrease in Δf (Hz) gave an estimate of 0.235 pg per MV.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2011

Simultaneous detection of surface coverage and structure of krypton films on gold by helium atom diffraction and quartz crystal microbalance techniques

We describe a quartz crystal microbalance setup that can be operated at low temperatures in ultra high vacuum with gold electrode surfaces acting as substrate surface for helium diffraction measurements. By simultaneous measurement of helium specular reflection intensity from the electrode surface and resonance frequency shift of the crystal during film adsorption, helium diffraction data can be correlated to film thickness. In addition, effects of interfacial viscosity on the helium diffraction pattern could be observed. To this end, first, flat gold films on AT cut quartz crystals were prepared which yield high enough helium specular reflection intensity. Then the crystals were mounted in the helium diffractometer sample holder and driven by means of a frequency modulation driving setup. Different crystal geometries were tested to obtain the best quality factor and preliminary measurements were performed on Kr films on gold surfaces. While the crystal structure and coverage of krypton films as a function of substrate temperature could successfully be determined, no depinning effects could be observed.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1975

Cryogenic Quartz Crystal Microbalance

A radiatively cooled Cryogenic Quartz Crystal Microbalance designed to monitor highly volatile contaminants on the shuttle is described. Measurements are made with two 15-MHz microbalances having removable, optically polished sensors mounted in a radiant cooler. One sensor operates below the freezing point of water and monitors contamination including that of water vapor. The second sensor is heated and monitors the contamination background. It provides a reference from which the density of the water vapor cloud enveloping the shuttle is determined. The design incorporates a low-power dissipation oscillator, heaters for ice removal, and a method for attaching second-surface mirrors to the radiator employing an indium type solder instead of a room temperature vulcanizer.

D Mckeown↗
NASA NTRS2004

Quartz Crystal Microbalance Operation and In Situ Calibration

Quartz crystal microbalances (QCMs) are commonly used to measure the rate of deposition of molecular species on a surface. The measurement is often used to select materials with a low outgassing rate for applications where the material has a line of sight to a contamination-sensitive surface. A quantitative, in situ calibration of the balance, or balances, using a pure material for which the enthalpy of sublimation is known, is described in this Technical Memorandum. Supporting calculations for surface dwell times of deposited materials and the effusion cell Clausing factor are presented along with examples of multiple QCM measurements of outgassing from a common source.

Albyn, K. C.↗
DOE OSTI2021

A practical guide to quartz crystal microbalance with dissipation monitoring of thin polymer films

Quartz crystal microbalance with dissipation (QCM-D) monitoring is a powerful tool used to sensitively examine the real-time responses of polymer films to external responses. For example, the technique is commonly used to monitor film growth, material adsorption, thin film swelling, and ion exchange. With its rapidly expanding use, this review is intended to introduce new users to the basic principles of QCM-D, along with practical challenges and remedies specific to polymer thin films. For both new and experienced users, specific case studies are highlighted including layer-by-layer assembly, electrochemical QCM-D, swelling, sensing, and biological application. Finally, the review recommends future directions for research and areas of growth.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Troubleshoot Quartz Crystal Microbalance Measurements Data

We are using a Qpod quartz crystal microbalance (manufactured by Inficon) for use as a low-volume non-volatile residue analysis tool. Inficon has agreed to help troubleshoot some of our measurements and are requesting to view some sample data, which are attached. The basic principle of an NVR analysis is to evaporate a known volume of solvent, and weigh the remaining residue to determine the purity of the solvent. A typical NVR analysis uses 60 g of solvent and can measure residue with an accuracy of +/- 0.01 mg. The detection limit is thus (0.01 mg)/(60 g) = 0.17 ppm. We are attempting to use a quartz crystal microbalance (QCM) to make a similar measurement. The attached data show the response of the QCM as a 5-20 mg drop of solvent evaporates on its surface. The change in mass registered by the QCM after the drop evaporates is the residue that deposits on the crystal. On some measurements, the change in mass in less than zero, which is aphysical since the drop will leave behind ≥0 mass of residue. The vendor, Inficon, has agreed to look at these data as a means to help troubleshoot the cause.

42 ENGINEERING↗
DOE OSTI2019

Elucidating mechanisms of oxide growth and surface passivation on zinc thin film electrodes in alkaline solutions using the electrochemical quartz crystal microbalance

For this study, we utilized electrochemical quartz crystal microbalance to understand electrochemical passivation of the zinc electrode in alkaline media and subsequent oxide growth and stripping. The formation of native zinc oxide on a near pristine Zn surface upon contact with 1 M KOH electrolyte was observed. The surface was seen to roughen with time. During Zn dissolution, the measured mass-charge ratio corresponded to the removal of ZnO and not merely Zn. The mechanism of passivation was determined to be caused by electrochemical etching to form pores. The etching leads to a build-up of solid ZnO and Zn(OH) 2 due to electrochemical reactions on the surfaces of the pores. These reactions functionally close the pores off from the bulk. The cycle of Zn deposition and dissolution develops a porous network, which may be the origin of mossy Zn deposits that plague reversible Zn metal batteries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗